In his seminal book On Growth and Form, mathematician and biologist D'Arcy Thompson presented his "theory of transformation," that a species evolves into another species not through a series of minor changes to various body parts but through large-scale transformations of the entire animal, and that the growth and form of any species of plant or animals can be represented through relatively simple mathematical equations. For example, he used linear and non-linear functions to show how the corresponding bones of similar species are adapted to their function, and morphed images of baboon skulls into the skulls of related species, including other primates and humans. Thorough, literary, and surprisingly readable, Thompson's book has been described as among the finest single books to teach inquisitive readers about biology, chemistry, physics, and the power of creative thought.